/**************************************************************************
 * Copyright (C) 2012-2021  Unisound
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 **************************************************************************
 *
 * Description : loader_write.c
 * Author      : yzs.unisound.com
 * Date        : 2021.03.01
 *
 **************************************************************************/
#include <unistd.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <ctype.h>

unsigned int s_nTable[256] = {
	0x00000000, 0x04C11DB7, 0x9823B6E, 0xD4326D9, 0x130476DC, 0x17C56B6B, 0x1A864DB2,
	0x1E475005, 0x2608EDB8, 0x22C9F00F, 0x2F8AD6D6, 0x2B4BCB61, 0x350C9B64, 0x31CD86D3,
	0x3C8EA00A, 0x384FBDBD, 0x4C11DB70, 0x48D0C6C7, 0x4593E01E, 0x4152FDA9, 0x5F15ADAC,
	0x5BD4B01B, 0x569796C2, 0x52568B75,  0x6A1936C8, 0x6ED82B7F, 0x639B0DA6, 0x675A1011,
	0x791D4014, 0x7DDC5DA3, 0x709F7B7A, 0x745E66CD,  0x9823B6E0, 0x9CE2AB57, 0x91A18D8E,
	0x95609039,0x8B27C03C, 0x8FE6DD8B, 0x82A5FB52, 0x8664E6E5,  0xBE2B5B58, 0xBAEA46EF,
	0xB7A96036,0xB3687D81, 0xAD2F2D84, 0xA9EE3033, 0xA4AD16EA, 0xA06C0B5D,  0xD4326D90,
	0xD0F37027,0xDDB056FE, 0xD9714B49, 0xC7361B4C, 0xC3F706FB, 0xCEB42022, 0xCA753D95,
	0xF23A8028,0xF6FB9D9F, 0xFBB8BB46, 0xFF79A6F1, 0xE13EF6F4, 0xE5FFEB43, 0xE8BCCD9A,
	0xEC7DD02D,0x34867077, 0x30476DC0, 0x3D044B19, 0x39C556AE, 0x278206AB, 0x23431B1C,
	0x2E003DC5,0x2AC12072,  0x128E9DCF, 0x164F8078, 0x1B0CA6A1, 0x1FCDBB16, 0x18AEB13,
	0x54BF6A4,0x808D07D, 0xCC9CDCA,  0x7897AB07, 0x7C56B6B0, 0x71159069, 0x75D48DDE, 0x6B93DDDB,
	0x6F52C06C, 0x6211E6B5, 0x66D0FB02,  0x5E9F46BF, 0x5A5E5B08, 0x571D7DD1, 0x53DC6066,
	0x4D9B3063, 0x495A2DD4, 0x44190B0D, 0x40D816BA,  0xACA5C697, 0xA864DB20, 0xA527FDF9,
	0xA1E6E04E, 0xBFA1B04B, 0xBB60ADFC, 0xB6238B25, 0xB2E29692,  0x8AAD2B2F, 0x8E6C3698,
	0x832F1041, 0x87EE0DF6, 0x99A95DF3, 0x9D684044, 0x902B669D, 0x94EA7B2A,  0xE0B41DE7,
	0xE4750050, 0xE9362689, 0xEDF73B3E, 0xF3B06B3B, 0xF771768C, 0xFA325055, 0xFEF34DE2,
	0xC6BCF05F, 0xC27DEDE8, 0xCF3ECB31, 0xCBFFD686, 0xD5B88683, 0xD1799B34, 0xDC3ABDED,
	0xD8FBA05A,  0x690CE0EE, 0x6DCDFD59, 0x608EDB80, 0x644FC637, 0x7A089632, 0x7EC98B85,
	0x738AAD5C, 0x774BB0EB,  0x4F040D56, 0x4BC510E1, 0x46863638, 0x42472B8F, 0x5C007B8A,
	0x58C1663D, 0x558240E4, 0x51435D53,  0x251D3B9E, 0x21DC2629, 0x2C9F00F0, 0x285E1D47,
	0x36194D42, 0x32D850F5, 0x3F9B762C, 0x3B5A6B9B,  0x315D626, 0x7D4CB91, 0xA97ED48,
	0xE56F0FF, 0x1011A0FA, 0x14D0BD4D, 0x19939B94, 0x1D528623,  0xF12F560E, 0xF5EE4BB9,
	0xF8AD6D60, 0xFC6C70D7, 0xE22B20D2, 0xE6EA3D65, 0xEBA91BBC, 0xEF68060B,  0xD727BBB6,
	0xD3E6A601, 0xDEA580D8, 0xDA649D6F, 0xC423CD6A, 0xC0E2D0DD, 0xCDA1F604, 0xC960EBB3,
	0xBD3E8D7E, 0xB9FF90C9, 0xB4BCB610, 0xB07DABA7, 0xAE3AFBA2, 0xAAFBE615, 0xA7B8C0CC,
	0xA379DD7B,  0x9B3660C6, 0x9FF77D71, 0x92B45BA8, 0x9675461F, 0x8832161A, 0x8CF30BAD,
	0x81B02D74, 0x857130C3,  0x5D8A9099, 0x594B8D2E, 0x5408ABF7, 0x50C9B640, 0x4E8EE645,
	0x4A4FFBF2, 0x470CDD2B, 0x43CDC09C,  0x7B827D21, 0x7F436096, 0x7200464F, 0x76C15BF8,
	0x68860BFD, 0x6C47164A, 0x61043093, 0x65C52D24,  0x119B4BE9, 0x155A565E, 0x18197087,
	0x1CD86D30, 0x29F3D35, 0x65E2082, 0xB1D065B, 0xFDC1BEC,  0x3793A651, 0x3352BBE6,
	0x3E119D3F, 0x3AD08088, 0x2497D08D, 0x2056CD3A, 0x2D15EBE3, 0x29D4F654,  0xC5A92679,
	0xC1683BCE, 0xCC2B1D17, 0xC8EA00A0, 0xD6AD50A5, 0xD26C4D12, 0xDF2F6BCB, 0xDBEE767C,
	0xE3A1CBC1, 0xE760D676, 0xEA23F0AF, 0xEEE2ED18, 0xF0A5BD1D, 0xF464A0AA, 0xF9278673,
	0xFDE69BC4,  0x89B8FD09, 0x8D79E0BE, 0x803AC667, 0x84FBDBD0, 0x9ABC8BD5, 0x9E7D9662,
	0x933EB0BB, 0x97FFAD0C,  0xAFB010B1, 0xAB710D06, 0xA6322BDF, 0xA2F33668,0xBCB4666D,
	0xB8757BDA, 0xB5365D03, 0xB1F740B4,
};

unsigned int CRC32(unsigned char * pBuffer, unsigned int nstage1_size)
{
	unsigned int nResult = 0xFFFFFFFF;
	while (nstage1_size--) nResult = (nResult << 8) ^ s_nTable[(nResult >> 24) ^ *pBuffer++];
	return nResult;
}

static unsigned long simple_strtoul(const char *cp,char **endp,unsigned int base)
{
	unsigned long result = 0,value;

	if (*cp == '0') {
		cp++;
		if ((*cp == 'x') && isxdigit(cp[1])) {
			base = 16;
			cp++;
		}
		if (!base) {
			base = 8;
		}
	}
	if (!base) {
		base = 10;
	}
	while (isxdigit(*cp) && (value = isdigit(*cp) ? *cp-'0' : (islower(*cp)
					? toupper(*cp) : *cp)-'A'+10) < base) {
		result = result*base + value;
		cp++;
	}
	if (endp)
		*endp = (char *)cp;
	return result;
}

static void help(void)
{
	printf("./loader_write.elf inputfile outputfile head_size stage1_size stage1_copy_count\n\n");
}

int main(int argc, char* argv[])
{
	int stage1_size;
	int stage1_copy_count;
	int header_size;
	int ret, i;
	unsigned int crc_res;
	unsigned char *buf;
	FILE *file_r, *file_w;

	if (argc < 6) {
		help();
		goto exit;
	}

	file_r = fopen( argv[1], "r");
	if (file_r == 0) {
		printf("file_r open err.\n");
		goto exit;
	}

	file_w = fopen( argv[2], "w+");
	if (file_r == 0) {
		printf("file_w open err.\n");
		fclose(file_r);
		goto exit;
	}

	header_size = simple_strtoul((const char *)argv[3], NULL, 10);
	stage1_size = simple_strtoul((const char *)argv[4], NULL, 10);
	stage1_copy_count = simple_strtoul((const char *)argv[5], NULL, 10);

	buf = malloc(stage1_size);
	memset(buf, 0xff, stage1_size);

	ret = fread(buf, 1, stage1_size, file_r);
	if (ret != stage1_size) {
		printf("read failed %d.\n", ret);
		goto close;
	}

	crc_res = CRC32(buf + header_size, stage1_size - 4 - header_size);
	*(unsigned int *)(buf + stage1_size - 4) = crc_res;

	for(i = 0; i < stage1_copy_count; i++) {
		ret = fwrite(buf, 1, stage1_size, file_w);
		if (ret != stage1_size) {
			printf("make %s from %s failed .\n",argv[2],argv[1]);
			goto close;
		}
	}

	/* write whole loader.bin */
	fseek( file_r, stage1_size, SEEK_SET);

	while(1) {
		ret = fread(buf, 1, stage1_size, file_r);
		fwrite(buf, 1, ret, file_w);
		if (ret < stage1_size)
			break;
	}

close:
	fclose(file_r);
	fclose(file_w);
	free(buf);

exit:
	exit(0);
}

